The ESP32-C3 BTHome Sensor Board is an open-source PCB designed for compact, battery-powered environmental and automation sensors communicating over Bluetooth Low Energy (BLE) using the BTHome v2 protocol.

It is based on the ESP32-C3 microcontroller, offering integrated Wi-Fi and BLE 5.0 connectivity, low power consumption, and flexible GPIO configuration.

The board supports a wide range of sensors and peripherals through I²C and 1-Wire interfaces, making it ideal for DIY smart home projects, automation nodes, or standalone monitoring units.

Key Features

MCU: ESP32-C3 (RISC-V, Wi-Fi + BLE 5.0)

Interfaces: I²C (SDA/SCL), 1-Wire, ADC for battery voltage measurement

Sensor compatibility: AHT10, BME280, BH1750, DS18B20, and other I²C/1-Wire modules

Power management: Integrated voltage divider for Li-Ion/Li-Po monitoring and I²C power control pin for low-power operation

Wireless communication: Bluetooth Low Energy with BTHome v2 advertisements (ready for Home Assistant integration)

Low-power design: Supports deep sleep with configurable wake intervals

Form factor: Compact layout optimized for small enclosures or direct battery connection

Typical Applications

Home Assistant BLE sensor nodes

Battery-powered environmental monitors (temperature, humidity, light, air pressure)

IoT development and prototyping platform for BLE-based devices

Custom automation modules with low energy footprint

The project includes open firmware examples for ESPHome and Arduino (C++), allowing easy customization and rapid prototyping.